Rep. Duncan Hunter considers himself the Republicans’ best bet to reconstitute the blue-collar coalition that helped the party win the White House in the 1980s.

Mr. Hunter, who is seeking the presidential nomination in 2008, says he can rebuild that coalition by campaigning on defense, traditional values and fair trade.

“Keeping American jobs in this country is a strong tie between the Republican Party and working America, Main Street America — that’s a portion of our constituency I aim to retrieve, because I stand strong with them,” the 13-term congressman from California said in a recent interview, pointing to votes against almost every free-trade agreement during his 26 years in the Capitol.

Mr. Hunter, the first to announce officially that he is exploring a run for president, presents a curious figure among better-known candidates.

Combined with a tough stance on border security — he was the author of the original amendment proposing 700 miles of border fence included in the House’s 2005 immigration bill — he fills a niche among the candidates lining up for a presidential run.

“I stand for a strong national defense, strong border enforcement, fiscal conservatism and traditional values, and lastly, keeping American jobs onshore,” he said as he sprawled in an armchair in his Capitol Hill office during the interview, propping one foot on the edge of his cluttered desk.

Mr. Hunter said he expects the next election to turn on security. He said his experience as an Army Ranger during the Vietnam War and as the top Republican on the House Armed Services Committee puts him squarely in the middle of that debate.

“I think it’s going to be a dangerous world. I think that’s going to have our attention, and I think we’re going to see a dangerous century,” he said.

Mr. Hunter is the most conservative candidate to enter the field so far, and is as conservative as any of the others mentioned as potential candidates. He touts his sponsorship of the Right to Life Act, which effectively would outlaw abortion by specifying that a person exists at the moment of fertilization, for the purposes of 14th Amendment protections.

Mr. Hunter easily has won re-election in his San Diego-based congressional district every election since his first, with the exception of a tight race in 1992 after redistricting and revelations of overdrafts at the now-defunct House bank.

His biggest challenges will be gaining name recognition and raising money. He has not been known as a prolific fundraiser on the scale of other announced candidates, but he has pledged to make a serious effort in early primary and caucus states.

Mr. Hunter made his preliminary announcement before the midterm elections Nov. 7 and, in the weeks since, raised his profile on television and in radio interviews.

Since the elections, both Sen. John McCain, Arizona Republican, and former New York Mayor Rudolph W. Giuliani have formed exploratory committees on races for president.

Mr. Hunter said he will make a formal announcement later, joking that this way he gets two press conferences out of it.

Mr. Hunter has been involved in many big defense-policy fights of the past few years. He was one of the strongest supporters of the way U.S. troops performed at the detention center at U.S. Naval Base Guantanamo Bay, Cuba.

In one memorable press conference at the Capitol, he brought a plate with lemon chicken, rice and the rest of the food that terror-war detainees were fed.

Mr. Hunter also took on the White House over women in combat and helped lead the opposition that blocked passage of the intelligence-overhaul bill in 2004 until the White House agreed to allow the defense intelligence agencies continued latitude to operate.

He has collected the endorsement of Rep. Trent Franks, Arizona Republican, who noted the move was curious given that his home-state colleague, Mr. McCain, has formed his own exploratory bid and is widely considered the candidate to beat.

But Mr. Franks said Mr. Hunter is the right man to lead the nation in a time of war and has his “wholehearted support.”